296 



among the cotton plants by cotton stainers [Dysdercus'] and also by 

 bush-bugs such as Nezara viridula. Further investigations are 

 necessary in connection with N. viridula and other insects causing 

 indirect attacks of disease on cotton and it is hoped that, as investi- 

 gations proceed, means for combating the attacks will be found. 

 Steps have already been taken to control by legislation and inspection 

 the times of sowing of cotton seed and the destruction of the old cotton 

 bushes at the end of each season, so that there shall be a period in 

 each year during which no cotton plants exist, thus depriving both 

 insect and fungus enemies of the means of surviving from one season 

 to another. Many leguminous crops are preferred food-plants of 

 these bugs, and, if these are abruptly destroyed, the insects then 

 invade the cotton in large numbers, probably carrying the disease with 

 them. Leguminous crops should therefore be so timed that they 

 may not have to be removed at a period when there is cotton that 

 might become infected. 



Haeland (S. C). The Inheritance of Immunity to Leaf-Blister Mite 

 {Eriophyes gossypii, Banks) in Cotton. — West Indian Bull, 

 Barbados, xvii, no. 3, 1919, pp. 162-166. [Received 19th May 

 1919.] 



The question of the immunity of certain types of cotton to Eriophyes 

 gossypii has been discussed in a previous paper and some account 

 has been given of crossing immune and susceptible varieties [see this 

 Review, Ser. A, v, p. 109]. The present paper contains an account of 

 the results of the F/1, F/2 and F/3 generations of a cross between 

 the immune type, St. Vincent native, and the susceptible type, Southern 

 Cross Upland. The F/1 was intermediate, though inclining towards 

 the susceptible parent. In F/2, segregation occurred into immune 

 and non-immune. In F/3 immune bred true, while non-immune 

 segregated into immune and non-immune. The economic importance 

 of the discovery that strains of cotton immune to the attacks of 

 E. gossypii can be obtained is obvious, as it opens up the way to the 

 production of immune strains of Sea Island cotton. The nature of 

 this immunity is briefly discussed. 



Ballou (H. a.). The Poisoning of the Boll Weevil. — Agric. News, 

 Barbados, xviii, no. 443, 19th April 1919, pp. 122-123. 



Owing to the success of experiments in the United States to control 

 the Mexican boll-weevil [Anthonomus grandis] on a large scale by 

 means of poisons, particulars are given as to the method adopted and 

 machinery used. 



The poison recommended is a calcium arsenate containing not less 

 than 40 per cent, arsenic pentoxide and not more than 0*75 per cent, 

 of water-soluble arsenic, and of a density not less than 80 cubic inches 

 per lb. The poison is applied in the form of a dust, 6 lb. being required 

 per acre for each apphcation. The fields should be sprayed from two 

 to four times during the season ; in the event of heavy rain within 

 24 hours, the dusting should be repeated. The best time to apply 



